zephyr/kernel/priority_queues.c

120 lines
2.7 KiB
C

/*
* Copyright (c) 2018,2024 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <zephyr/kernel.h>
#include <ksched.h>
#include <zephyr/sys/math_extras.h>
void z_priq_dumb_remove(sys_dlist_t *pq, struct k_thread *thread)
{
ARG_UNUSED(pq);
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
sys_dlist_remove(&thread->base.qnode_dlist);
}
struct k_thread *z_priq_dumb_best(sys_dlist_t *pq)
{
struct k_thread *thread = NULL;
sys_dnode_t *n = sys_dlist_peek_head(pq);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_dlist);
}
return thread;
}
bool z_priq_rb_lessthan(struct rbnode *a, struct rbnode *b)
{
struct k_thread *thread_a, *thread_b;
int32_t cmp;
thread_a = CONTAINER_OF(a, struct k_thread, base.qnode_rb);
thread_b = CONTAINER_OF(b, struct k_thread, base.qnode_rb);
cmp = z_sched_prio_cmp(thread_a, thread_b);
if (cmp > 0) {
return true;
} else if (cmp < 0) {
return false;
} else {
return thread_a->base.order_key < thread_b->base.order_key
? 1 : 0;
}
}
void z_priq_rb_add(struct _priq_rb *pq, struct k_thread *thread)
{
struct k_thread *t;
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
thread->base.order_key = pq->next_order_key++;
/* Renumber at wraparound. This is tiny code, and in practice
* will almost never be hit on real systems. BUT on very
* long-running systems where a priq never completely empties
* AND that contains very large numbers of threads, it can be
* a latency glitch to loop over all the threads like this.
*/
if (!pq->next_order_key) {
RB_FOR_EACH_CONTAINER(&pq->tree, t, base.qnode_rb) {
t->base.order_key = pq->next_order_key++;
}
}
rb_insert(&pq->tree, &thread->base.qnode_rb);
}
void z_priq_rb_remove(struct _priq_rb *pq, struct k_thread *thread)
{
__ASSERT_NO_MSG(!z_is_idle_thread_object(thread));
rb_remove(&pq->tree, &thread->base.qnode_rb);
if (!pq->tree.root) {
pq->next_order_key = 0;
}
}
struct k_thread *z_priq_rb_best(struct _priq_rb *pq)
{
struct k_thread *thread = NULL;
struct rbnode *n = rb_get_min(&pq->tree);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_rb);
}
return thread;
}
struct k_thread *z_priq_mq_best(struct _priq_mq *pq)
{
struct k_thread *thread = NULL;
for (int i = 0; i < PRIQ_BITMAP_SIZE; ++i) {
if (!pq->bitmask[i]) {
continue;
}
#ifdef CONFIG_64BIT
sys_dlist_t *l = &pq->queues[i * 64 + u64_count_trailing_zeros(pq->bitmask[i])];
#else
sys_dlist_t *l = &pq->queues[i * 32 + u32_count_trailing_zeros(pq->bitmask[i])];
#endif
sys_dnode_t *n = sys_dlist_peek_head(l);
if (n != NULL) {
thread = CONTAINER_OF(n, struct k_thread, base.qnode_dlist);
break;
}
}
return thread;
}